430 research outputs found
Fast diffusion of graphene flake on graphene layer
Diffusion of a graphene flake on a graphene layer is analyzed and a new
diffusion mechanism is proposed for the system under consideration. According
to this mechanism, rotational transition of the flake from commensurate to
incommensurate states takes place with subsequent simultaneous rotation and
translational motion until the commensurate state is reached again, and so on.
The molecular dynamics simulations and analytic estimates based on ab initio
and semi-empirical calculations demonstrate that the proposed diffusion
mechanism is dominant at temperatures T ~ Tcom, where Tcom corresponds to the
barrier for transitions of the flake between adjacent energy minima in the
commensurate states. For example, for the flake consisting of ~ 40, 200 and 700
atoms the contribution of the proposed diffusion mechanism through rotation of
the flake to the incommensurate states exceeds that for diffusion of the flake
in the commensurate states by one-two orders of magnitude at temperatures 50 -
150 K, 200 - 600 K and 800 - 2400 K, respectively. The possibility to
experimentally measure the barriers to relative motion of graphene layers based
on the study of diffusion of a graphene flake is considered. The results
obtained are also relevant for understanding of dynamic behavior of polycyclic
aromatic molecules on graphene and should be qualitatively valid for a set of
commensurate adsorbate-adsorbent systems.Comment: 33 pages, 6 figure
Preserving the Memory of the Great Patriotic War among Young People on the Example of the Social Project “Saved Childhood”
В статье рассматривается результат реализации социального проекта «Спасенное детство» как формы работы с молодежью по сохранению исторической памяти о Великой Отечественной войне. Также приведены оценки проекта всех участников: организаторов, участников‑школьников, ветеранов (эвакуированных детей Ленинграда).The article considers the result of the social project “Saved childhood” as a form of work with young people to preserve the historical memory of the great Patriotic war. The project is also evaluated by all participants: organizers, participants-school children, veterans (evacuated children of Leningrad)
Methodical recommendation to "Basics of software engineering. Laboratory practice". Part 1
Software engineering is an engineering discipline that is concerned with all aspects of software production. Software engineering can be divided into sub-disciplines. Some of them are: - Software engineering management: The application of management activities – planning, coordinating, measuring, monitoring, controlling, and reporting – to ensure that the development and maintenance of software is systematic, disciplined, and quantified. Requirements engineering: The elicitation, analysis, specification, and validation of requirements for software
Methodical recommendation to "Basics of software engineering. Laboratory practice". Part 1
Software engineering is an engineering discipline that is concerned with all aspects of software production. Software engineering can be divided into sub-disciplines. Some of them are: - Software engineering management: The application of management activities – planning, coordinating, measuring, monitoring, controlling, and reporting – to ensure that the development and maintenance of software is systematic, disciplined, and quantified. Requirements engineering: The elicitation, analysis, specification, and validation of requirements for software
Knowledge Management as a Strategy for the Administration of Education in the Research University
The article studies the substantiation of the changes in the Classical University when its liberal model is transforming into the pragmatic model in modern knowledge society. The content of pragmatic model (commercialization of knowledge, education market, competitions) is against its classical model. Therefore, there is a need to clarify the criteria of the Classical University. The corporate culture is considered as its new criterion. The corporate culture aimed towards shaping of the professional and the person who is relevant to the modern knowledge society. Therefore, the modern Research University continues the traditional Idea of the Classical University in conditions of information (knowledge) society. Secondly, new strategy for the management of education in the Research University is the knowledge management. Thirdly, the corporate culture of the Research University can join complementarily the classical criteria of University and modern orientation to the market and commercialization of education. The specific content of the corporate culture as a new criterion of the University is relevant to the conditions of information or knowledge society. The corporate culture of the Research University provides not only competitiveness of professional, but also in its spiritual and moral characteristics
Ab Initio Calculations of the Walls Shear Strength of Carbon Nanotubes
The dependence of the energy of interwall interaction in double-walled carbon
nanotubes (DWNT) on the relative position of walls has been calculated using
the density functional method. This dependence is used to evaluate forces that
are necessary for the relative telescopic motion of walls and to calculate the
shear strength of DWNT for the relative sliding of walls along the nanotube
axis and for their relative rotation about this axis. The possibility of
experimental verification of the obtained results is discussed.Comment: 4 pages, 1 figur
Use of a recombinant human follicle-stimulating hormone:recombinant human luteinizing hormone (r-hFSH:r-hLH) 2:1 combination for controlled ovarian stimulation during assisted reproductive technology treatment: A real-world study of routine practice in the Russian Federation
Two observational studies in the Russian Federation described patient demographics/clinical decision for treatment with recombinant human follicle-stimulating hormone:recombinant human luteinizing hormone (r-hFSH:r-hLH) 2:1 combination for ovarian stimulation (OS) during assisted reproductive technology (ART) and outcomes, respectively. The first (prospective) study enrolled 500 patients. After post-hoc regrouping to assign patients to discrete groups, 378 (75.6%) met the local Russian label for an r-hFSH:r-hLH 2:1 combination, 105 (21%) were treated according to other physician preference, and 17 (3.4%) met only the ESHRE Bologna criteria for a poor ovarian response. The clinical pregnancy rate per cycle was 30.4%. A total of 158/175 (90.3%) women achieving clinical pregnancy in the prospective study participated in the second (retrospective) study. The live birth rate per cycle was 25.8%. No new safety concerns were reported. These results support the use of the r-hFSH:r-hLH 2:1 combination in patients with a poor/suboptimal response to OS for ART treatment in the Russian Federation
Market restrictions on the lifting and transportation equipment production
Over the past few decades, the trends of globalization and the markets expansion have been fundamental in the Russian and world economies. Such economic structure requires a large volume and range of transportation, the storage systems presence, the transported objects distribution. Logistics centers become an integral part of the economic development both for the regions and the country as a whole. Logistics centers, in turn, need specialized equipment that allows the most efficient use of existing storage areas. Reach truck is one of the most commonly used equipment in large A and A + warehouses. The article presents the estimating market restrictions method when the equipment cost determining taking into account the characteristics of the designed facility and the main competitors represented on the market. The method peculiarity is taking into account the technical and consumer characteristics of the investigated object, their comparison with the competitors' parameters. Based on this comparison, the possible product price is determined. The proposed technique allows to optimize equipment configuration and price depending on the consumers' needs. The proposed evaluation algorithm was tested on complex technical equipment (reach truck), but it should be noted that the proposed methodology is universal and can be applied to any technical object. © Published under licence by IOP Publishing Ltd
Efficiency of <i>in vitro</i> culture techniques applied to soybean (<i>Glycine max (L.) Merr.</i>) accessions from the VIR collection
Using a wide range of modern biotechnologies and genetic techniques to study plant germplasm accessions held by VIR makes it possible to procure valuable results, required for the development of new high-yielding cultivars adapted to adverse environmental conditions and possessing specified technological properties, particularly to identify and mark new genes and alleles useful for plant breeding. This research trend is in line with Presidential Decree No. 680 “Concerning the development of genetic technologies in the Russian Federation”. Soybean is among the key crops in agricultural production, but the use of next-generation breeding tools to obtain new soybean cultivars with desired properties is still limited. Successful application of novel methods also requires new approaches to studying soybean accessions, specifically their ability to regenerate and produce calluses for subsequent inclusion in biotechnological programs.Ten soybean accessions of various origin, contrasting in ripening schedules, were selected to study the possibility of effective introduction into in vitro culture and further assessment of their ability to produce calluses and regenerate in in vitro culture. The work included evaluating the effects of different seed sterilization techniques (one-step sterilization, using a commercial bleach, and two-step one, combining the impacts of a chlorine-containing preparation and hydrogen peroxide), types of explants (epicotyls, hypocotyls, cotyledon nodes, and cotyledon leaf segments), and phytohormone composition of nutrient medium: (1) MS + 1.13 mg/L BAP + 0.5 mg/L HA, and (2) MS +1 mg/L BAP + 0.1 mg/L IAA).The assessment results showed that the option of two-step seed sterilization was the most effective for soybean at the stage of in vitro culture initiation, while hypocotyls, epicotyls, and cotyledon nodes had the highest callus formation ability in both types of nutrient media
Рифтовые системы шельфа Российской Восточной Арктики и арктического глубоководного бассейна: связь геологической истории и геодинамики
In our study, we have developed a new tectonic scheme of the Arctic Ocean, which is based mainly on seismic profiles obtained in the Arctic-2011, Arctic-2012 and Arctic-2014 Projects implemented in Russia. Having interpreted many seismic profiles, we propose a new seismic stratigraphy of the Arctic Ocean. Our main conclusions are drawn from the interpretation of the seismic profiles and the analysis of the regional geological data. The results of our study show that rift systems within the Laptev, the East Siberian and the Chukchi Seas were formed not earlier than Aptian. The geological structure of the Eurasian, Podvodnikov, Toll and Makarov Basins is described in this paper. Having synthesized all the available data on the study area, we propose the following model of the geological history of the Arctic Ocean: 1. The Canada Basin formed till the Aptian (probably, during Hauterivian-Barremian time). 2. During the Aptian-Albian, large-scale tectonic and magmatic events took place, including plume magmatism in the area of the De Long Islands, Mendeleev Ridge and other regions. Continental rifting started after the completion of the Verkhoyansk-Chukotka orogenу, and rifting occurred on the shelf of the Laptev, East Siberian, North Chukchi and South Chukchi basins, and the Chukchi Plateau; simultaneously, continental rifting started in the Podvodnikov and Toll basins. 3. Perhaps the Late Cretaceous rifting continued in the Podvodnikov and Toll basins. 4. At the end of the Late Cretaceous and Paleocene, the Makarov basin was formed by rifting, although local spreading of oceanic crust during its formation cannot be excluded. 5. The Eurasian Basin started to open in the Early Eocene. We, of course, accept that our model of the geological history of the Arctic Ocean, being preliminary and debatable, may need further refining. In this paper, we have shown a link between the continental rift systems on the shelf and the formation history of the Arctic Ocean.На основе российских сейсмических профилей, полученных в рамках проектов Арктика-2011, Арктика-2012 и Арктика-2014, составлена новая тектоническая схема Арктического океана. Приведены результаты интерпретации многих сейсмических профилей, представлена новая сейсмостратиграфия для Арктического океана. Основные выводы сделаны на основе интерпретации сейсмических профилей и на базе анализа региональных геологических данных. Показано, что рифтовые системы в пределах морей Лаптевых, Восточно-Сибирского и Чукотского были образованы не раньше аптского времени. Дано описание геологического строения бассейнов Евразийского, Подводников, Толля, Макарова и других. На основе синтеза всех данных получена следующая модель истории Арктического океана. 1. Канадский бассейн был образован до аптского времени (вероятно, в готериве-барреме). 2. В апте-альбе были крупномасштабные тектонические и магматические события: плюмовый магматизм был в районе поднятия Де-Лонга, на хребте Менделеева и в других областях. Континентальный рифтинг произошел сразу после окончания Верхоянско-Чукотской орогении и рифтинг был на шельфе морей Лаптевых, Восточно-Сибирского, Северо-Чукотского и Южно-Чукотского и на поднятии Чукотского плато; одновременно континентальный рифтинг начался в бассейнах Подводников и Толля. 3. В позднем мелу рифтинг, возможно, продолжился в бассейнах Подводников и Толля. 4. В конце позднего мела и в палеоцене в ходе рифтинга был образован бассейн Макарова; локальный спрединг океанической коры при формировании бассейна Макарова не исключен. 5. Евразийский бассейн начал образовываться в начале эоцена. Наша модель геологической истории Арктического океана является предварительной и дискуссионной. В целом, мы показали связь континентальных рифтовых систем на шельфах с историей раскрытия Арктического океана
- …